EP1515045A2 - Gear motor with start up control - Google Patents
Gear motor with start up control Download PDFInfo
- Publication number
- EP1515045A2 EP1515045A2 EP04077511A EP04077511A EP1515045A2 EP 1515045 A2 EP1515045 A2 EP 1515045A2 EP 04077511 A EP04077511 A EP 04077511A EP 04077511 A EP04077511 A EP 04077511A EP 1515045 A2 EP1515045 A2 EP 1515045A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- motor according
- housing
- fluid
- cavity
- channel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
- F04C14/06—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations specially adapted for stopping, starting, idling or no-load operation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
- F03C2/00—Rotary-piston engines
- F03C2/08—Rotary-piston engines of intermeshing-engagement type, i.e. with engagement of co- operating members similar to that of toothed gearing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
- F04C15/0023—Axial sealings for working fluid
- F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2/00—Rotary-piston machines or pumps
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C2/18—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with similar tooth forms
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0088—Lubrication
Definitions
- the present invention relates to hydraulic motors.
- Hydraulic motors are well known for converting fluid energy into mechanical energy in a system. Hydraulic motors may comprise a number of different basic configurations but a widely used type of motor is one known as a gear motor.
- a gear motor uses a pair of intermeshing gear elements rotating within a housing. High pressure fluid delivered to an inlet induces rotation of the gear elements and causes a corresponding rotation of a shaft connected to one of the gear elements.
- Such motors are relatively inexpensive and are capable of handling relatively high pressures.
- the end faces of the gear sets are sealed with a pressure compensating seal assembly in which the pressure of the fluid delivered to the inlet is applied to the seal to ensure close contact with the end faces. Whilst this arrangement improves the efficiency of the motor in use, it can lead to difficulties in initial starting of the motor.
- the high contact force provided by the pressure compensated seal inhibits rotation of the motor, particularly where the motor is connected to high inertia loads such as a cooling fan or mower reel.
- the present invention provides a gear type hydraulic motor in which pressure fluid is introduced in discrete areas between the gear faces and a pressure compensated seal to improve lubrication upon start up.
- a hydraulic motor comprising a housing having a fluid inlet, a fluid outlet and a cavity therebetween.
- a pair of intermeshing gear elements are rotatable in the housing about mutually parallel axes.
- Each of the gear elements have a set of gear teeth disposed about the periphery of the element and a support shaft extending from oppositely directed end faces of the set of gear teeth.
- a bearing assembly is located on opposite sides of the cavity in the housing to support the shafts for rotation about respective ones of the axes.
- Each of the bearing assemblies has a sealing face overlying the end faces and biased into engagement with the end faces by a pressure compensating seal located between the bearing and the housing.
- the sealing face has a channel extending partially about the spindle and a fluid communication with the inlet to introduce fluid under pressure between the faces.
- Figure 1 is an exploded perspective view of a hydraulic motor.
- Figure 2 is a view on the line 2-2 of Figure 1.
- Figure 3 is a perspective view on an enlarged scale showing the bearing and seal assemblies of the motor.
- Figure 4 is an end view of a bearing block shown in Figure 3.
- Figure 5 is a view on the line V-V of Figure 4.
- a hydraulic motor generally indicated 10 has a body 12 with an internal cavity 14.
- a pair of end caps 16, 18 are connected to the housing 12 through bolts 20 and pins 22.
- a seal 24 between the end caps 16, 18 and housing 12 provides a hydraulically sealed unit.
- Fluid is introduced into the cavity 14 through an inlet 26 and flows out of the cavity through a similar outlet duct 27 ( Figure 4) on the opposite wall.
- End cap 16 also houses a pressure relief valve assembly 28 to avoid excess pressure in the cavity 14.
- the cavity 14 houses motor elements collectively indicated at 30.
- the motor elements are best seen in Figure 3 and comprise a pair of gear elements 32, 34.
- Each of the gear elements has a set of gear teeth 36, 38 disposed about respective shafts 40, 42.
- the sets of gear teeth 36, 38 have radial extending end faces 44.
- the shafts 40, 42 are supported at opposite ends in bearing 46, 48.
- Each of the bearings 46, 48 is similar and has a planar end face 50 arranged opposite the end faces 44.
- the shafts 40, 42 are received in respective cylindrical bores 52 and the bearings are a sliding fit in the respective end caps 16, 18.
- the oppositely directed face 54 of the bearings 46, 48 supports a pressure compensating seal assembly 56.
- the seal assembly 56 has tangs 58 located in notches 60 on the bearing to maintain it in position.
- the seal 56 and bearings 46, 48 are located within the cavity 42 so that the sets of gear teeth 36, 38 are inter-engaged for conjoint rotation.
- One end of the shaft 42 projects through a bore in the end cap 18 and is sealed by a shaft seal 62.
- the end face 50 of each of the bearings is formed with a channel 64 that extends from a groove 66 in opposite directions about each of the shafts 40, 42.
- the groove 66 opens onto the high pressure side of the motor 10, that is in fluid communication with the inlet 26, and the channel 64 extends partially about the shaft and terminates prior to the lower pressure zone adjacent the outlet 27.
- the channel is located between the root diameter and major diameter of the tooth and in the embodiment shown is centred on the pitch circle of the gear sets 36, 38 so as to be partially covered by each tooth of the gear.
- the channel 64 extends over an arc in the order of 165° to 220° although in general, the arc should extend sufficiently about the shaft to terminate just prior to the connection of fluid contained within adjacent gear teeth with the low pressure zone hydraulically connected to the outlet.
- the channel 50 extends 55° beyond a line joining the centres of rotation of the shafts 40, 42, indicated by the arc in Figure 4 so as to terminate prior to the point at which the housing and gear teeth separate adjacent the outlet 27.
- the width of channel 64 is selected to provide sufficient area to counter balance the forces imposed by the pressure compensated seal 56 and, in a particular embodiment tested, a width of between 0.8 mm and 1.1 mm extending on a radius between 12.7 mm and 13.0 mm over an arc of 220° measured from the root of the grove 66 provided a effective surface area of 74 mm 2 .
- the depth of the channel 64 was 1.5 to 1.0 mm.
- high pressure fluid is introduced into the inlet 26 and, through action on the gear sets 36, 38 causes rotation in opposite direction of the shafts 40, 42.
- Fluid from the inlets is delivered to the pressure compensating seal assembly that biases the bearings 46, 48 toward the end faces 44 of the gear sets 36, 38.
- Pressure fluid is also delivered to the notch 66 and carried in the channel 64 about the shaft to counter the force of the pressure compensating seal.
- the channel 64 also permits lubricant to flow between the end faces 44 and the face 50 of the bearing and provide lubrication in a controlled manner to the end faces. Accordingly, upon start up of the motor 10, the clamping force induced by the seal 56 on the end faces 44 is reduced by the force exerted from fluid in the channel 64 and the presence of lubricant at the end faces.
- the location of the groove 64 between the root diameter and major diameter of the tooth permits the fluid to flow between the faces of the teeth 36, 38 and the end face 50 to provide lubrication to each of the teeth 36, 38.
- a location on the pitch circle diameter has been used in testing.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Hydraulic Motors (AREA)
- Rotary Pumps (AREA)
Abstract
Description
- The present invention relates to hydraulic motors.
- Hydraulic motors are well known for converting fluid energy into mechanical energy in a system. Hydraulic motors may comprise a number of different basic configurations but a widely used type of motor is one known as a gear motor. A gear motor uses a pair of intermeshing gear elements rotating within a housing. High pressure fluid delivered to an inlet induces rotation of the gear elements and causes a corresponding rotation of a shaft connected to one of the gear elements.
Such motors are relatively inexpensive and are capable of handling relatively high pressures. - To improve the efficiency of the motor, the end faces of the gear sets are sealed with a pressure compensating seal assembly in which the pressure of the fluid delivered to the inlet is applied to the seal to ensure close contact with the end faces. Whilst this arrangement improves the efficiency of the motor in use, it can lead to difficulties in initial starting of the motor. The high contact force provided by the pressure compensated seal inhibits rotation of the motor, particularly where the motor is connected to high inertia loads such as a cooling fan or mower reel.
- It is accordingly an object of the present invention to provide a motor which the above disadvantages are obviated or mitigated.
- In general terms, the present invention provides a gear type hydraulic motor in which pressure fluid is introduced in discrete areas between the gear faces and a pressure compensated seal to improve lubrication upon start up.
- According therefore to the present invention there is provided a hydraulic motor comprising a housing having a fluid inlet, a fluid outlet and a cavity therebetween. A pair of intermeshing gear elements are rotatable in the housing about mutually parallel axes. Each of the gear elements have a set of gear teeth disposed about the periphery of the element and a support shaft extending from oppositely directed end faces of the set of gear teeth. A bearing assembly is located on opposite sides of the cavity in the housing to support the shafts for rotation about respective ones of the axes. Each of the bearing assemblies has a sealing face overlying the end faces and biased into engagement with the end faces by a pressure compensating seal located between the bearing and the housing. The sealing face has a channel extending partially about the spindle and a fluid communication with the inlet to introduce fluid under pressure between the faces.
- An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:
- Figure 1 is an exploded perspective view of a hydraulic motor.
- Figure 2 is a view on the line 2-2 of Figure 1.
- Figure 3 is a perspective view on an enlarged scale showing the bearing and seal assemblies of the motor.
- Figure 4 is an end view of a bearing block shown in Figure 3.
- Figure 5 is a view on the line V-V of Figure 4.
- Referring therefore to Figure 1, a hydraulic motor generally indicated 10 has a
body 12 with aninternal cavity 14. A pair ofend caps 16, 18 are connected to thehousing 12 throughbolts 20 andpins 22. Aseal 24 between theend caps 16, 18 andhousing 12 provides a hydraulically sealed unit. - Fluid is introduced into the
cavity 14 through aninlet 26 and flows out of the cavity through a similar outlet duct 27 (Figure 4) on the opposite wall.End cap 16 also houses a pressurerelief valve assembly 28 to avoid excess pressure in thecavity 14. Thecavity 14 houses motor elements collectively indicated at 30. The motor elements are best seen in Figure 3 and comprise a pair ofgear elements gear teeth respective shafts gear teeth - The
shafts bearings planar end face 50 arranged opposite the end faces 44. Theshafts cylindrical bores 52 and the bearings are a sliding fit in therespective end caps 16, 18. The oppositely directedface 54 of thebearings seal assembly 56. Theseal assembly 56 hastangs 58 located innotches 60 on the bearing to maintain it in position. - As can better be seen in Figure 2, the
seal 56 andbearings cavity 42 so that the sets ofgear teeth shaft 42 projects through a bore in the end cap 18 and is sealed by ashaft seal 62. - Referring once more to Figure 3, and to Figure 4, the
end face 50 of each of the bearings is formed with achannel 64 that extends from agroove 66 in opposite directions about each of theshafts groove 66 opens onto the high pressure side of themotor 10, that is in fluid communication with theinlet 26, and thechannel 64 extends partially about the shaft and terminates prior to the lower pressure zone adjacent theoutlet 27. In the preferred embodiment, the channel is located between the root diameter and major diameter of the tooth and in the embodiment shown is centred on the pitch circle of thegear sets channel 64 extends over an arc in the order of 165° to 220° although in general, the arc should extend sufficiently about the shaft to terminate just prior to the connection of fluid contained within adjacent gear teeth with the low pressure zone hydraulically connected to the outlet. In one embodiment, thechannel 50 extends 55° beyond a line joining the centres of rotation of theshafts outlet 27. The width ofchannel 64 is selected to provide sufficient area to counter balance the forces imposed by the pressure compensatedseal 56 and, in a particular embodiment tested, a width of between 0.8 mm and 1.1 mm extending on a radius between 12.7 mm and 13.0 mm over an arc of 220° measured from the root of thegrove 66 provided a effective surface area of 74 mm2. The depth of thechannel 64 was 1.5 to 1.0 mm. - In operation, high pressure fluid is introduced into the
inlet 26 and, through action on thegear sets shafts bearings gear sets notch 66 and carried in thechannel 64 about the shaft to counter the force of the pressure compensating seal. Thechannel 64 also permits lubricant to flow between the end faces 44 and theface 50 of the bearing and provide lubrication in a controlled manner to the end faces. Accordingly, upon start up of themotor 10, the clamping force induced by theseal 56 on the end faces 44 is reduced by the force exerted from fluid in thechannel 64 and the presence of lubricant at the end faces. - As may be seen from Figures 4 and 5, the location of the
groove 64 between the root diameter and major diameter of the tooth permits the fluid to flow between the faces of theteeth end face 50 to provide lubrication to each of theteeth - In testing conducted with a motor having a capacity of, A, it was found that the starting torque was decreased by 15% to 29% with a
channel 64 of the dimensions detailed above. It will be seen therefore that by providing thechannel 64 in the end faces of thebearings - Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto.
Claims (10)
- A hydraulic motor comprising a housing having a fluid inlet, a fluid outlet and a cavity there between, a pair of intermeshing gear elements rotatable in said cavity about mutually parallel axes, each of said gear elements having a set of gear teeth disposed about the periphery of said element and a support shaft extending from oppositely directed end faces of said set of gear teeth, a bearing assembly located on opposite sides of said cavity in said housing to support said shafts for rotation about respective ones of said axes, each of said bearing assemblies having a sealing face overlying said end faces and biased into engagement with said end face by a pressure compensating seal located between said bearing and said housing, said sealing face having a channel extending partially about said spindle and in fluid communication with said inlet to introduce fluid under pressure between said faces.
- A motor according to claim 1 wherein said channel is accuate and is centred on said axis of rotation.
- A motor according to claim 2 wherein said channel is located between a root diameter and major diameter of each gear teeth.
- A motor according to claim 3 wherein said channel is located on a pitch circle of gear teeth.
- A motor according to claim 1 wherein said bearing assembly is integrally formed to support both if said shafts and a pair of channels extend about respective ones of said gears.
- A motor according to claim 5 wherein said channels intersect at said inlet.
- A motor according to claim 4 wherein said channels are located between a root diameter and major diameter of said teeth.
- A motor according to claim 7 wherein said channels are located on the pitch circle of said teeth.
- A motor according to claim 6 wherein said channels extend over an are of 180°.
- A motor according to claim 9 wherein said channels extend over an arc of 165°.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US659704 | 1996-06-10 | ||
US10/659,704 US6902382B2 (en) | 2003-09-11 | 2003-09-11 | Gear motor start up control |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1515045A2 true EP1515045A2 (en) | 2005-03-16 |
EP1515045A3 EP1515045A3 (en) | 2006-10-11 |
Family
ID=34136763
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04077511A Withdrawn EP1515045A3 (en) | 2003-09-11 | 2004-09-10 | Gear motor with start up control |
Country Status (2)
Country | Link |
---|---|
US (1) | US6902382B2 (en) |
EP (1) | EP1515045A3 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITBO20110025A1 (en) * | 2011-01-25 | 2012-07-26 | Trw Automotive Italia S R L | PUMPING GROUP TO SUPPLY OIL IN PRESSURE TO A USER |
EP2657525A3 (en) * | 2012-04-27 | 2015-12-30 | Robert Bosch Gmbh | Gear machine with an axial seal stretching into the area of radial exterior surface of the correponding bearing support |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005002757B4 (en) * | 2005-01-20 | 2018-04-26 | Trw Automotive Gmbh | Power steering system hydraulic pump |
US20080056887A1 (en) * | 2006-06-09 | 2008-03-06 | Entire Interest | Hydraulic gear motor with integrated filter |
US20080063554A1 (en) * | 2006-09-08 | 2008-03-13 | Gifford Thomas K | Precision flow gear pump |
DE102007060758A1 (en) * | 2007-12-17 | 2009-06-18 | Robert Bosch Gmbh | liquid pump |
DE102009012916A1 (en) * | 2009-03-12 | 2010-09-16 | Robert Bosch Gmbh | Hydraulic gear machine |
DE202010007466U1 (en) * | 2010-06-01 | 2011-09-28 | Wegener International Gmbh | Manual welding device |
JP6350744B2 (en) * | 2015-05-13 | 2018-07-04 | 株式会社島津製作所 | Gear pump |
GR1009196B (en) * | 2016-08-31 | 2018-01-11 | Αθανασιος Νικολαου Κοτουπας | New-type gear system |
GB201617119D0 (en) * | 2016-10-07 | 2016-11-23 | Rolls-Royce Controls And Data Services Limited | Gear pump bearing |
US10470380B2 (en) * | 2016-10-28 | 2019-11-12 | Deere & Company | Lubrication system |
FR3125849A1 (en) * | 2021-07-27 | 2023-02-03 | Eaton Intelligent Power Limited | Pressure control on a slide bearing |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2865302A (en) * | 1955-05-18 | 1958-12-23 | Thompson Prod Inc | Pressure-loaded gear pump |
US2891483A (en) * | 1956-04-13 | 1959-06-23 | Thompson Ramo Wooldridge Inc | Movable bushing for pressure loaded gear pumps |
US3251309A (en) * | 1963-04-12 | 1966-05-17 | Parker Hannifin Corp | Industrial gear pump |
EP0151798A1 (en) * | 1984-02-11 | 1985-08-21 | Robert Bosch Gmbh | Gear pump or motor |
US6390793B1 (en) * | 2001-02-13 | 2002-05-21 | Haldex Barnes Corporation | Rotary gear pump with fluid inlet size compensation |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3830602A (en) * | 1973-03-14 | 1974-08-20 | Commercial Shearing | Rotary pumps and motors |
DE2403319A1 (en) * | 1974-01-24 | 1975-07-31 | Bosch Gmbh Robert | GEAR MACHINE |
DE2421599A1 (en) * | 1974-05-04 | 1975-11-13 | Bosch Gmbh Robert | GEAR PUMP |
DE2610827A1 (en) * | 1976-03-15 | 1977-09-29 | Bosch Gmbh Robert | GEAR MACHINE (PUMP OR MOTOR) |
FR2543229B1 (en) * | 1983-03-22 | 1985-08-16 | Hydroperfect Int | DEVICE FOR HYDROSTATIC COMPENSATION OF GEAR TYPE HYDRAULIC PUMPS AND MOTORS |
-
2003
- 2003-09-11 US US10/659,704 patent/US6902382B2/en not_active Expired - Lifetime
-
2004
- 2004-09-10 EP EP04077511A patent/EP1515045A3/en not_active Withdrawn
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2865302A (en) * | 1955-05-18 | 1958-12-23 | Thompson Prod Inc | Pressure-loaded gear pump |
US2891483A (en) * | 1956-04-13 | 1959-06-23 | Thompson Ramo Wooldridge Inc | Movable bushing for pressure loaded gear pumps |
US3251309A (en) * | 1963-04-12 | 1966-05-17 | Parker Hannifin Corp | Industrial gear pump |
EP0151798A1 (en) * | 1984-02-11 | 1985-08-21 | Robert Bosch Gmbh | Gear pump or motor |
US6390793B1 (en) * | 2001-02-13 | 2002-05-21 | Haldex Barnes Corporation | Rotary gear pump with fluid inlet size compensation |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITBO20110025A1 (en) * | 2011-01-25 | 2012-07-26 | Trw Automotive Italia S R L | PUMPING GROUP TO SUPPLY OIL IN PRESSURE TO A USER |
WO2012101588A3 (en) * | 2011-01-25 | 2013-03-14 | Trw Automotive Italia S.R.L. | Pumping assembly for feeding oil under pressure to a user |
EP2657525A3 (en) * | 2012-04-27 | 2015-12-30 | Robert Bosch Gmbh | Gear machine with an axial seal stretching into the area of radial exterior surface of the correponding bearing support |
Also Published As
Publication number | Publication date |
---|---|
US20050058566A1 (en) | 2005-03-17 |
EP1515045A3 (en) | 2006-10-11 |
US6902382B2 (en) | 2005-06-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6902382B2 (en) | Gear motor start up control | |
US20110200477A1 (en) | Gerotor hydraulic pump | |
US6171089B1 (en) | External gear pump with drive gear seal | |
EP2837827B1 (en) | Hydraulic device | |
EP0153076B1 (en) | Gerotor motor and improved lubrication flow circuit therefor | |
US4171938A (en) | Fluid pressure operated pump or motor | |
EP2918839B1 (en) | Electric pump | |
JPH01247767A (en) | Internal contact gear motor | |
EP1549854B1 (en) | Integrated speed reducer and pump assembly | |
US4177025A (en) | High-pressure rotary fluid-displacing machine | |
EP0302728A2 (en) | Rotary valve plate | |
EP0310292A2 (en) | Bearing bush for a gear pump | |
GB2383611A (en) | Rotary vane-type machine | |
JPS63259105A (en) | Rotary piston engine | |
JP3011796B2 (en) | Internal gear pump for hydraulic fluid | |
US3781149A (en) | Rotary fluid-pressure machines | |
US6685453B2 (en) | Fluid transfer machine with drive shaft lubrication and cooling | |
WO1997020145A1 (en) | Axial sealing | |
US20170335846A1 (en) | Gear Pump | |
EP0029356B1 (en) | Pressure gradient controlled rotary hydraulic machine | |
EP0701661B1 (en) | Gear pump with controlled clamping force | |
EP0555909A1 (en) | Rotary pump with simplified pump housing | |
JP4061847B2 (en) | Gear pump | |
EP0819218B1 (en) | Positive displacement hydraulic machines | |
JP2002106476A (en) | Gear pump |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL HR LT LV MK |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL HR LT LV MK |
|
17P | Request for examination filed |
Effective date: 20070402 |
|
AKX | Designation fees paid |
Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
17Q | First examination report despatched |
Effective date: 20080314 |
|
R17C | First examination report despatched (corrected) |
Effective date: 20080404 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20081015 |